Technical Field
The present invention relates to building automation and more specifically to occupancy sensors.
Background Art
Efficient and productive use of space and resources is an increasingly important goal for businesses and organizations. Given current concerns about energy costs and public perception, this trend should continue for the foreseeable future. Occupancy sensors are a crucial component in realizing this goal.
Occupancy sensors are a common component in many buildings. Typically mounted on ceilings, occupancy sensors detect the presence of occupants within an area. They are most commonly used to control the power delivered to electrical loads, specifically lights, depending on the occupancy of the monitored area. For example, an occupancy sensor may be used to turn off a light in an office when occupancy hasn't been sensed for a period of time, thereby conserving electricity. Conversely, after a period of vacancy, the occupancy sensor may conveniently turn on the light upon sensing occupancy after a period of vacancy. Typically, a signal is transmitted to a switching device, such as a relay or a power pack, to control the load.
Although most commonly used to directly control a load, occupancy sensors are increasingly employed in control systems such as Building Automation Systems (BAS). BASs, also known as Building Management Systems (BMS) and Energy Management Systems (EMS), are employed in buildings and structures to control and monitor a building's mechanical and electrical equipment. BASs are implemented in buildings in varying degrees of complexity and increase efficiency by exploiting relationships of interrelated components and sharing information to more accurately meet demand. In addition to controlling a load, occupancy sensors employed in BASs may also be networked to other components in the system to share information. Networked occupancy sensors may transmit and receive information to other network components such as other occupancy sensors and central controllers.
Building designers and managers now desire and there is now a need for an occupancy sensor with improved functionality.